A matrix having many rows and one column is known as?

A. Row matrix

B. Column matrix

C. Diagonal matrix

D. None of the mentioned

This question was addressed to me in unit test.

The doubt is from Types of Matrices in section Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Right answer is B. Column matrix

The best I can explain: In column matrix there is only one column.